Alumnus Crowley’s Foursquare in NY Times

Last Monday night in Austin, about 200 people were milling around the bar at the Driskill Hotel, an unofficial headquarters for the name-badge-infested horde attending the South by Southwest Music and Media Conference. And just after midnight, about 70 people in different parts of the gorgeous relic of a bar stood up and began moving quickly toward the exit.

Where were we all going? To the CollegeHumor party around the corner. How did we know it was time to go there? Because our smartphones told us so.

At large events, people have always moved in groups to the next big thing. But at the interactive portion of the conference, the ubiquity of so-called ubiquitous presence — location-based services like Foursquare and Gowalla — meant the hive suddenly knew what it was collectively doing. (Although some truisms still attain: The party was nothing special once we got there.)

It was striking to see the digital location effect in the wild, with people reacting to an unseen dog whistle and moving en masse, on command. Location-based services work like this: People sign in at their location and a list of nearby bars and restaurants (or in the instance of the conference, parties and panels) appears, along with a list of people you know who are there.

This year, Foursquare had an application that ranked locations by number of check-ins, so social heat was defined as lists were populated. The nerdy digital merit badges handed out for checking in at various locations included a few customized ones for Austin, among them a Porky badge for checking in on at least two barbecue places. The most ubiquitous presence has bragging rights over a particular spot, becoming the “mayor,” which sometimes includes a free meal or drink. (The New York Times provided content to Foursquare in a partnership for the Winter Games.)

At the Driskill and many other places during the conference, people moved out because others began signaling their arrival somewhere else by “checking in” — sending a notice of their arrival to Foursquare. (It wasn’t just parties, either. The hive knew that the Twitter keynote panel bombed because all kinds of people who were there began checking in elsewhere.)

If that sounds like old news — Foursquare made its debut here in 2009 — consider that much larger companies are just now bolting location awareness onto their existing applications. Twitter, with 50 million messages a day, introduced a location-awareness function during the conference, while Facebook, with more than 400 million users worldwide, will soon flip the switch for the 100 million or so users who update on smartphones.

Yelp, a popular listing of user-generated reviews, has added a check-in feature, and Google just added a widget to its Latitude application that lets you see the location of nearby pals who have enabled the service. Similarly, Apple has applied for patents for iGroup, which will give its iPhone users real-time information on who is nearby.

To someone not in their 20s whose location generally isn’t that interesting to others — that would be me — the idea of handing over your privacy with both hands to strap on a digital ankle bracelet sounds profoundly unattractive. (I was probably the mayor of taking a disco nap before heading out for another long evening at South by Southwest so I wouldn’t keel over.) But to a younger cohort that lives on the grid, the location of people you know and care about is vital information, the coin of the realm.

“For many, the benefits of augmented reality outweigh issues of privacy,” said Beka Economopoulos of Fission Strategy, a Web development and social media consulting firm for nonprofits. And it often leads to a digitally enabled “lemming effect,” she added.

Location awareness would only seem to be of use in dense urban areas — in many small towns and suburbs, everyone already knows where everyone else is. But what if location became not just a physical place, but a digital one? The possibilities for old and new media could be significant.

“The check-in is bigger than location,” said Yancey Strickler of Kickstarter, a Web site that helps with fund-raising for media products. “Think of media: Checking into watching ‘Lost,’ being declared the mayor of ‘The Brothers Karamazov’ or earning a badge for braving free jazz.”

What if a highly influential person suddenly became the mayor of your obscure little webcast, new book or you saw that your friends were checking in on a critically acclaimed but struggling new network show? Cue the lemmings and viral things might happen. For the time being, Foursquare and others limit check-ins to physical locations, but that could change.

“It doesn’t just have to be about where to get a good cup of coffee,” said Dennis Crowley, a co-founder of Foursquare. “It could be about a certain type of movie and then perhaps you’d get an offer of another movie in that category. Right now, we are focused on place because we have a small team, but eventually, we could support check-ins to anything. It’s really about experiences people have had.” (We talked over lunch at Stubb’s, a legendary Austin barbecue spot, and yes, he got the Porky badge.)

Logic suggests that the advertising possibilities enabled by knowing where someone is or what they have been watching at a given moment are profound. If the first movers gain users and the big boys come off the sidelines, what looks like a fetish object could end up being one more important tool in navigating physical and digital space.

Location was the talk of Austin, the maypole we all literally pivoted around, and the bounce seemed back, at least in social media. There were dueling parties between Foursquare and Gowalla, an Austin-based service, on Monday night: Foursquare had both Ashton Kutcher and a bubble machine at the Cedar Street Courtyard, while just around the corner at the Belmont, Gowalla had a tie-in to Lance Armstrong’s LiveStrong foundation and a D.J. set by Diplo. Life on and off the grid was full of free booze and ambient awareness, with social maps on iPhones lighting the way.

As I left Austin, it was nice to find out on Foursquare that others had stopped at the Salt Lick barbecue restaurant at the Austin airport on their way out of town and bought a brisket sandwich. But then again, the aroma as I walked by probably told me what I needed to know, no P.D.A. or check-ins required.